Alert archive / Iowa / Flash Flood Warnings in 2011

Flash Flood Warning 21, NWS La Crosse, WI

September 3, 2011Fayette County, Iowa

NWS La Crosse, WI issued this flash flood warning at Sep 3, 2011, 1:46 AM CDT for Fayette County, Iowa. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Sep 3, 2011, 1:46 AM CDT (06:46 UTC)
Expired
Sep 3, 2011, 5:47 AM CDT
In force
4 hr
Issued by
NWS La Crosse, WI
Area
Storm-based polygon
Flood severity
None

County Fayette County, IA

The radar

The La Crosse radar (KARX), 136 km from the middle of the area, began a volume at 06:46 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 6.8 hours before the alert went out and 170 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Davenport, at 00:00Z on 2011-09-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1861 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 00:00Z on 2011-09-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 87 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
1861 J/kg
Mixed-layer CIN
-107 J/kg
Mixed-layer LCL
1596 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
87 m²/s²
0-3 km storm-relative helicity
165 m²/s²
Significant tornado parameter
0.2
Supercell composite
3.6

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

386 
WGUS53 KARX 030646
FFWARX
IAC065-031230-
/O.NEW.KARX.FF.W.0021.110903T0646Z-110903T1230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LA CROSSE WI
146 AM CDT SAT SEP 3 2011

THE NATIONAL WEATHER SERVICE IN LA CROSSE HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHERN FAYETTE COUNTY IN NORTHEAST IOWA...

* UNTIL 730 AM CDT

* AT 144 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SLOW MOVING THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE      
  WARNED AREA. DOPPLER RADAR ESTIMATED THAT UP TO 3 INCHES OF RAIN   
  HAS FALLEN OVER THE PAST 2 HOURS. ADDITIONAL RAINFALL OF 1 TO 2    
  INCHES WILL BE POSSIBLE OVER THE NEXT FEW HOURS.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
  OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...     
  OELWEIN...ARLINGTON...FAYETTE AND MAYNARD. SOME RIVERS AND STREAMS 
  THAT WILL EXPERIENCE FLOODING INCLUDE THE LITTLE WAPSIPINICON      
  RIVER...OTTER CREEK AND THE LITTLE VOLGA RIVER.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLASH FLOODING IS OBSERVED ACT QUICKLY. DO
NOT ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND TO
ESCAPE FLOOD WATERS. DO NOT STAY IN AREAS SUBJECT TO FLOODING WHEN
WATER BEGINS RISING.

FLOODING IS OCCURRING OR IS IMMINENT. IT IS IMPORTANT TO KNOW WHERE
YOU ARE RELATIVE TO STREAMS...RIVERS...OR CREEKS WHICH CAN BECOME
KILLERS IN HEAVY RAINS. CAMPERS AND HIKERS SHOULD AVOID STREAMS OR
CREEKS.

&&

LAT...LON 4264 9209 4288 9209 4288 9161 4264 9161
      4264 9208

$$

HALBACH
3 follow-up statements
591 
WGUS73 KARX 030747
FFSARX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
247 AM CDT SAT SEP 3 2011

IAC065-031230-
/O.CON.KARX.FF.W.0021.000000T0000Z-110903T1230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
FAYETTE IA-
247 AM CDT SAT SEP 3 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR SOUTHERN FAYETTE COUNTY
UNTIL 730 AM CDT...

AT 245 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. 
DOPPLER RADAR ESTIMATES THAT 3 TO 4 INCHES OF RAIN HAS FALLEN OVER 
THE PAST FEW HOURS WITH AN ADDITIONAL HALF INCH OF RAIN POSSIBLE 
THROUGH 4 AM.

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO 
OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING 
INCLUDE...OELWEIN...ARLINGTON...FAYETTE AND MAYNARD. SOME RIVERS AND 
STREAMS THAT WILL EXPERIENCE FLOODING INCLUDE THE LITTLE VOLGA 
RIVER...LITTLE WAPSIPINICON RIVER...AND OTTER CREEK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLOODING OF SMALL CREEKS
AND STREAMS...COUNTRY ROADS...NORMALLY DRY WASHES... AS WELL AS
FARMLAND ALONG THE BANKS OF CREEKS AND STREAMS.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLOODING IS OBSERVED...ACT QUICKLY. DO NOT
ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND. DO NOT
STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

FLOODING IS OCCURRING OR IS IMMINENT. IT IS IMPORTANT TO KNOW WHERE
YOU ARE RELATIVE TO STREAMS...RIVERS...OR CREEKS WHICH CAN BECOME
KILLERS IN HEAVY RAINS. CAMPERS AND HIKERS SHOULD AVOID STREAMS OR
CREEKS.

&&

LAT...LON 4264 9209 4288 9209 4288 9161 4264 9161
      4264 9208

$$

HALBACH
006 
WGUS73 KARX 030845
FFSARX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
345 AM CDT SAT SEP 3 2011

IAC065-031230-
/O.CON.KARX.FF.W.0021.000000T0000Z-110903T1230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
FAYETTE IA-
345 AM CDT SAT SEP 3 2011

...FLASH FLOOD WARNING REMAINS IN EFFECT FOR SOUTHERN FAYETTE COUNTY
UNTIL 730 AM CDT...

AT 341 AM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS THE WARNED AREA. 
DOPPLER RADAR ESTIMATES SHOW THAT 3 TO 4 INCHES OF RAIN HAS FALLEN 
ACROSS PORTIONS OF SOUTHERN FAYETTE COUNTY.

RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE FLASH FLOODING TO
OCCUR. SOME LOCATIONS THAT WILL EXPERIENCE FLOODING 
INCLUDE...WESTGATE...OELWEIN...ARLINGTON...FAYETTE AND MAYNARD. SOME 
RIVERS AND STREAMS THAT WILL EXPERIENCE FLOODING INCLUDE THE LITTLE 
WAPSIPINICON RIVER...THE LITTLE VOLGA RIVER...OTTER CREEK...AND STOE 
CREEK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODING. IF FLOODING IS OBSERVED...ACT QUICKLY. DO NOT
ENTER THE WATER. TURN AROUND AND MOVE UP TO HIGHER GROUND. DO NOT
STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

FLOODING IS OCCURRING OR IS IMMINENT. IT IS IMPORTANT TO KNOW WHERE
YOU ARE RELATIVE TO STREAMS...RIVERS...OR CREEKS WHICH CAN BECOME
KILLERS IN HEAVY RAINS. CAMPERS AND HIKERS SHOULD AVOID STREAMS OR
CREEKS.

&&

LAT...LON 4264 9209 4288 9209 4288 9161 4264 9161
      4264 9208

$$

HALBACH
790 
WGUS73 KARX 031047
FFSARX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LA CROSSE WI
547 AM CDT SAT SEP 3 2011

IAC065-031058-
/O.CAN.KARX.FF.W.0021.000000T0000Z-110903T1230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
FAYETTE IA-
547 AM CDT SAT SEP 3 2011

...THE FLASH FLOOD WARNING THAT WAS IN EFFECT FOR SOUTHERN FAYETTE
COUNTY IS CANCELLED...

HEAVY RAINFALL HAS EXITED EAST OF THE AREA. CALLS TO LAW ENFORCEMENT 
INDICATED THERE WAS NO FLOODING OBSERVED. SCATTERED SHOWERS AND 
THUNDERSTORMS WILL BE SEEN ACROSS THE AREA TODAY. HOWEVER... 
WIDESPREAD HEAVY RAINFALL IS NOT EXPECTED. IF FLOODING HAS BEEN 
OBSERVED IN YOUR AREA...PLEASE REPORT IT TO YOUR LOCAL LAW 
ENFORCEMENT AGENCY.

LAT...LON 4264 9209 4288 9209 4288 9161 4264 9161
      4264 9208

$$

DAS

The office that day

Everything else NWS La Crosse, WI issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 2, 11:58 PM CDTSevere Thunderstorm WarningARXClayton, Fayette62 min
Sep 3, 12:54 AM CDTSevere Thunderstorm WarningARXAllamakee, Clayton66 min
Sep 3, 2:13 AM CDTSevere Thunderstorm WarningARXClayton, Fayette47 min
Sep 3, 2:53 AM CDTFlash Flood WarningARXClayton3 hr

Nearby

Flash Flood Warnings in Iowa, 2011Every flash flood warning in 2011

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.